Switch



N. J. CONRAD Feb. 11, 1930.

SWITCH inal Filed Dec. 12, 1925 4 Sheets-Sheet 1 ma MAM N. J. CONRAD Feb. 11, 1930.

SWITCH inal Filed Dec. 12, 1925 4 Sheets-Sheet 2 Feb. 11, 1930. N. J. CONRAD 1,746,337

Feb. 11, 1930, N, .oNRAD' 1,746,337

inal Filed Dec. 12. 1925 4 Sheets-Sheet 4 my at Fatented Feh. ill,

7 a -er w Patient NICHOLAS J. CONRAD, WELMETTE, ILLIBTGIS, ASSIGNOR 1E0 $QHVIF'ITZEPI 8r, CQIBTEEQD, U1 CHICAGO, ILLINOIS, A QORLPQBATION 033 ILLINOIS SWITCH Original application filed December 12, 1925, Serial No. 24,530; Eatent No. 1,631,012, dated may 31, 1837. Divided and this application filed Bay 5, 1927. Serial 1310. 189,005.

My invention relates to switches, and more particularly to the class which is employed for interrupting current flow in open air. lVhile the particular embodiment which 1 have elected is an open air switch, it is to be understood that the invention is not limited to open air switches.

The particular feature of importance in the present invention is the employment of an electric fuse, preferably of high current rupturing capacity as a means for suppressing the are which would otherwise be formed at the main switch contacts by separation of such contacts.

1 am aware that a fuse of this character has been employed in a similar situation for suppressing the are which would otherwise be drawn at the main switch contacts, as shown, for example, in the patent to Schweit zer No. 1,211,967, of January 9, 1917, in which the main contacts of the switch are shunted by a fuse of high current interrupting capacity either at the instant when the contacts are separated or shortly thereafter, as shown in said patent. According to the present invention, the main switching contacts are separated by a motion which first breaks the main normal conducting path and which thereafter shunts the main contacts for a period suiiicient to establish a circuit through the fuse and to suppress any are which might begin to form at the main contacts, and then the main contacts continue their separating movement to include a further break between them and between one of those contacts and the fuse contact or terminal.

This idea may be embodied in a variety of switches relating to the locking means there for, the quick break mechanism therefor, the contactmechanism therefor, and other fea tures which will be apparent from the detailed description.

N ow, in order to acquaint those skilled in the art with the manner of constructing and operating a device embodying my invention, 1 shall describe in connection with the accompanyingdrawings a specific embodiment of the invention:

Fig. 1 is a side elevational view of the switch;

Fig. 2 is a like view of the same showing the switch in partly open position;

Fig. 2A is a diagram of the connections and mode of operation of the switch;

3 is a top plan view of the switch;

1 is a rear side elevational view of the switch shown;

Fig. 5 is an end elevation of the switch as viewed from the left end of Fig. 4;

Fig. 6 is a cross sectional View taken through the horizontal axis of the rea nd of the switch;

Fig. .7 is a fragmentary sectional view taken on the line 77 of Fig. 6;

Fig. 8 is a section through the switch taken on the line 88 of Fig. 8; and

Fig. 9 is a fragmentary view of a contact for the switch bar bearing the fuse for use in a modified embodiment of the switch shown in Figs. 1 to 1, inclusive.

This application is a division of my application for switch, Serial Number 74,930, filed December 12, 1925, and issued as Patent No. 1,631,012, of May31,1927.

1n the embodiment of my invention illustrated the fuse and its contact are relatively movable, as indicated in the diagram of F ig. 2A. The switch is mounted upon a suitable base 120 through insulators 121 and 122, the insulator 121 having a hinge contact 123 mounted thereupon, this hinge contact having the main switch blade 125 pivoted thereupon. The insulator 122 bears the split contact 124 for engaging with the free end of the blade 125.

A pair of guiding and locking horns 126 are mounted adjacent the split contact 124 The auxiliary or quick break blade 128 is hinged at its rear end on the screw 129 to the swinging loop 130 which is pivoted upon the main blade 125 adjacent its rear end. The quick break blade 128 is connected electrically to the main blade 125 by a flexible copper braided strap 131 and mechanically the two blades are connected together through the spring 132, one end of which is looped about the pin 133 upon each side of the arcing blade 128 and the central part of which spring extends over the top of the main blade 125, as indicated at 134, this part being held in a notch in the blade 125 by means of the screw 135 and there being helical coils as indicated at 136 upon each side of the main blade 125. The structure of the spring 132 permits pivoting of the quick break blade 128 about the screw 129 and also permits endwise motion of the blade 128, the loop 130 serving as a guide for the same. This endwise movement of the blade 129 is desirable when the switch is closed to permit the pin 137 to slide along the tapered edge of the catch or detent 127 and then to be projected under the shoulder of the same. The main blade 125 has an operating eye 138 pivoted on a cross pin 139, this operating eye having a hook extension 140 beyond the pivot 139 with a suitable notch 141 for engaging a pin 142 which is mounted crosswise in the quick break blade 128. A pair of stop pins 143 and 144 limit the/motion of the eye and its connected hook member 140. A spring 145, which is coiled about the pin 139, normally urges the hook member 140 in a clockwise direction as viewed in Fig. 1, to cause the slot 141 to catch the pin 142. I

The operation of the switch thus far described is as follows Assuming that the switch is in closed position as viewed in Fig. 1, the main blade 125 is pivoted on the hinge contact 123 and is embraced by the split contact 7 124. This main blade also lies between the guiding horns 126. The quick break blade 128 has its pin 137 caught under the shoulder127 and the forward end of this blade is engaged by a spring contact finger 146, this contact finger being riveted at its upper end, as indicated at 147, to the guiding horn 126 upon each side of the quick break blade 128. Since the blade 128 is locked by the detent 127 and since the main blade is locked to the quick break blade 128 through the hook member 140 and pin 142, it will be seen that the switch is thereby locked in closed position.

If, now, the operator wishes'to open the switch, the operating hook is inserted in the eye 138 and the eye is moved to the left as viewed in Fig. 1, thereby releasing the hook member 140 from the pin 142. Thereupon, the main blade 125 may be moved out of the split contact 124, as indicated in dotted lines in Fig. 1, the quick break blade 128 remaining in contact through the springs 146 and the guiding horns 126, because of the pin 137 which is still retained under the shoulder 127. Continued motion of the main blade withdraws the pin 137 from the shoulder 127 when the switch has moved to a position which is substantially open. It will be observed that the tendency of the spring 132 is to expand and keep the pin 137 under the shoulder 127.

As soon as the pin leaves contact with the shoulder 127, the spring 132 swings the blade 128 in a counter clockwise direction up into its normal position where the pin 142 is caught by the hook 140, as is illustrated in the dottedline position shown in Fig. 2.

The switch break mechanism which I have described is novel per se, and so is the lock which I have described. These mechanisms,

are combined, however, with a fuse of a suitable type for the purpose of causing the actual break or the greater part thereof to occur within the fuse while the main parts of the switch are separatin In the present case a fuse blade 148 is hinged to the main blade 125, as will be clear from Fig. 3.

Referring to Figs. 3, 6 and 7, it will be seen that I have disposed adjacent one side of the main blade.125 the base or leg 150 of a bracket member 149, and upon the other side of a plate 151 which is riveted to the blade. Plate 151 forms one leg of a U-shaped bracket, shown at 152 in Fig. 3, the opposite leg 153 of which extends outside of the outer leg of the bracket 149 The bracket 149 has its other leg 154 adjacent the leg.153 of the bracket 152, so that said bracket 149 is confined between the blade 125 on one side and the opposite leg of the bracket 152 on the other, with the shaft or pivot pin 155 extending through all of these parts and being pinned, as indicated at 156, to the plate 151 of bracket 152. The bracket 149 has an extension 157 to which is bolted the fuse blade 148, this blade being a strip of fibre or other suitable insulating material and having apparent.

are-ass? stead. This fuse is preferably of the type disclosed in my copending application, Serial No. 631,263, filed April 11, 1923. These fuses are mounted in fuse clips also disclosed in a co-pending application. These fuse clips are characterized by the employment of wire bails which serve to compress spring blades against the sides of the ferrules of the fuses and to hold the fuses against accidental removal from the fuse clips. The fuse which T have described has a cap which may be blown from the end thereof and such end is the upper end of the fuse.

The extension 157 on the bracket 149 has an integral stop finger 168 reaching under the main switch blade 125, the hinge pin 155 having a helical spring 169 coiled about the same and having its ends anchored in the bracket members 152 and 149, respectively, tending to hold the fuse blade 148 away from the main blade 125, that is, tending to move the fuse blade 148 with its fuse 164 in a clockwise direction with respect to the main blade 125, as viewed in Fig. 1. The flat loop spring 160 is in electrical connection with the split contact 124 and connected to one side of the line. This spring 160 has its one side 171 connected to one side of the U-shaped bracket 173, as shown in Fig. 4. The opposite side 174 serves as a stop for the free end of the spring 160. The latter arm 174 of bracket 173 is notched or slotted to receive the end of the contact member 159 and to hold the same against lateral displacement. The arm 175 of the spring 160 engages the end of the contact 159 and holds it in contact electrically and mechanically until-the main blade with its quick break contact has been moved a sutiicient distance to prevent re-establishment of the are at the main contact. The continued motion of the main switch blade then opens the fuse blade 148.

The operation of the switch will now be Then the main blade 125 is opened, the quick break blade 128 lingers in contact with the guiding horns 126 and the spring contact fingers 146 until the blade has reached a position where there is no danger of re-establishing the arc, whereupon the quick break blade 128 is snapped upwardly by the spring 132, throwing the fuse 164 into the circuit, and continued movement of the main blade causes the fuse blade 148 with its contact 159 to move away from the spring contact 160 to interpose a suitable space or air gap between the two parts of the switch.

Upon closing of the switch, the contact terminal member 159 of the fuse blade 148 will contact with spring 160, first, after which the main blade 125 will move into contact with the main split contact 124. As the main blade approaches full closed position, the pin 137 contacts with the inclined edge of the detent and forces the quick break blade toward the hinged end of the'main blade, against the action of spring 132. "When the main blade reaches full closed position, the blade 128 is projected toward the guiding horns 126 by spring 132 causing the pin 137 to be disposed beneath shoulder 127, efi'ectually locking the switch closed. In this manner the circuit is closed through the fuse and the main and quick break blades successively, and the switch is held closed in such manner as to prevent casual opening thereof.

The side members 150 and 154 of the brack et member 149, which support the fuse blade 148, are so arranged with respect to the bracket member 152 that after the main blade has reached a predetermined open position the fuse blade 148 will be moved with said main blade as though the two were rigidly connected together.

It is to be noted that the brackets 161 and i 167 set the fuse 164 ed to one side where the blowing of the fuse out of the end of the ferrule 163 will not affect the contacts 159 and 160, nor the main contacts 124 and 125.

If the switch is closed under load which may be sufficient to blow the fuse, the fuse is not inserted in its mounting on the auxiliary blade until after the switch is closed. If desired, a small ampere capacity fuse may be inserted on the mounting on the auxiliary blade when the switch is open, and employed as a test fuse to indicate that current will flow when the switch is closed. This is an important feature of the invention, particularly for installations where the switch is not to be closed under conditions where current will flow upon such closing. If the fuse blows it furnishes in such installations an indication that the switch should not be closed.

It will be apparent from the foregoing that I have provided a pair of main contacts which normally carry the current and which are adapted to be separated, the first result of which is to switch in a fuse of high current interrupting capacity which blows and interrupts the current. The circuit of the fuse is then broken by further opening movement of the main switch blade.

Normally, in the switch shown in Fig. 1, the quick break releases when the main blade is substantially at 45 position towards its fully open position. The fuse blade begins to open substantially at the time that the quick break blade'releases. The fuse blade travels with the main blade for substantially the rest of the movement of the main blade after about the first 45.

While in the constructions shown in igs. 1 to 8 the fuse is thrown immediately into circuit when the quick break blade 128 opens,

it will be apparent that the fuse contact 159 may be brought into engagement with the pair of opposed spring contact fingers 180, shown in Fig. 9, which may replace spring 160 and bracket 178, after the quick break of the main blade has started to open the circuit. v

In the modified form illustrated in Fig. 9, contact 159 is out of contact with fingers 180 when the switch is closed. As the main blade 125 is moved out of contact with the split contact 12-1, the fuse contact 159 is raised into contact with fingers 180, immediately after which the quick break blade 128 is released, by the continued movement of the main blade. The circuit is thus interrupted by the successive opening of the main blade 125, the quick break blade 128, and then the fuse blade 148. the final opening of the circuit occurring through the fuse 164. In closing the switch, the circuit is closed through the fuse and the main blade and the quick break blade, successively, contact 159 passing downwardly out of contact with fingers 180 as the main blade is moved into full closed position.

I do not intend to be limited to the details shown and described. Y

I claim 1. In combination, a stationary switch contact, a co-operating' movable switch contact, a fuse member movable with the movable switch contact away from the stationary switch contact only after the main switch contact has moved to predetermined open position.

2. In combination, a stationary switch contact, amovable main switch blade, a fuse blade pivoted at one end on the main blade and adapted at the opposite end to make contact with the switch contact, a fuse connected in series in said fuse blade, and means for moving the fuse blade to open position only after the main switch blade has moved to substantially open position.

3. In combination, a stationary switch terminal, a movable switch blade co-operat- 'ing therewith, a fuse blade, a fuse connected serially in the fuse blade. and means responsive to a predetermined movement of the main switch blade for initiating the opening movement of the fuse blade.

4. In combination, a stationary switch contact, a movable switch blade, said stationary switch contact having a shoulder, a

quick break blade pivoted to the main blade and having means engaging said shoulder when the switch'is in closed position, yieldable means holding the two blades together, and locking means connecting the main blade and the quick break blade.

5. In combination, a stationary switch contact, a pivoted blade co-operating therewith,

a quick break blade, a guide member mounted on the main switch blade and pivoted to the quick break blade, the stationary cont-acthaving a shoulder, and the quick break blade having a co-operat-ing shoulder for holding the quick break blade closed until the main blade has moved to a predetermined open position, and a spring member tending to move the quick break blade about its pivot toward the main blade, and tending to move the guide member along the main blade to hold the co-operating shoulders in engagement.

6. In combination, a stationary switch contact, a pivoted main blade co-operating therewith, a quick break blade, a guide member mounted on the main blade and pivoted to the quick break blade, the stationary contact having a shoulder, and the quick break blade having a co-operating shoulder for holding the quick break blade closed until the main blade has moved to a predetermined open position, a spring member tending to move the quick break blade about its pivot towards the main blade, and tending to move the guide member along the main blade to hold the co-operating shoulders in engagement, and manually releasable locking means connecting the main blade and the quick break blade.

7. In combination, a pair of switch terminals, a switch blade pivoted on one terminal, the other terminal having a contact member adapted to engage the main switch blade, a quick break switch blade pivoted to the main blade and having a shoulder engaging a shoulder on the main switch contact to hold the quickbreak blade incontact with the main switch contact until the main blade has moved to a predetermined open position, a fuse blade pivoted on the main switch blade and having a terminal adapted to engage the main switch terminal, a fuse connected in series in said fuse blade, said fuse being connected between the switch terminals when the quick break blade has moved to open position, and means on the main switch blade for thereafter moving the fuse arm to open position.

8; In combination, a hinge terminal, a free terminal, a main blade hinged to the hinge terminal, a quick break blade connected between the main blade and the free terminal, and a fuse blade connected between the main blade and the free terminal, and means for separating the main blade, thereafter the quick break blade, and thereafter the fuse blade, from the free switch terminal.

9. In combination, a'hinge contact, a free contact, a main blade pivoted to the hinge contact and adapted to engage the free contact, a quick break blade pivoted to the main blade and engaging the free contact, a fuse blade connecting the main blade and the free contact,=.and means for opening first the main blade, then the quick break blade, and then the fuse blade.

nveaaev 10. In combination, pair of switch con tacts, means for closing the contacts, and means efiective upon the actuation of the switch for connecting a fuse across said contacts before they are closed.

11. In a switch, a stationary contact, a conducting blade,a nonconducting fuse blade carrying a fuse and means for moving said blades, said means connecting the fuse in circuit before the conducting blade is closed.

12. In combination, a stationary main switch contact member, a movable main switch blade cooperating therewith, a fuse blade, a fuse mounted in series with said fuse blade, connections between said blades for opening the fuse blade subsequent to opening of the main blade and a supplemental contact member cooperating with the fuse blade and connected to said main contact member, the supplemental contact member being in contact with the fuse blade during movement of said fuse blade in opening direction through a predetermined distance.

13. In combination, a stationary main switch contact member, a movable main switch blade cooperating therewith, a fuse blade, a fuse mounted in series with said fuse blade, connections between said blades for opening the fuse blade subsequent to opening of the main blade, and a supplemental contact member disposed to contact with the fuse blade after it has been opened to a predetermined extent, the fuse blade being out of contact with the supplemental contact memher when said main blade is in full closed position.

14. In combination, a pair of relatively movable switch contacts, means for separating said contacts, a fuse permanently connected to one of said contacts, the other end of the fuse being connected to the other contact at the instan of separation of said contacts, and means for disconnecting the fuse from said last mentioned contact.

15. In combination, a pair of relatively separable main switch contacts, means for separating said contacts, a fuse adapted to be connected across said contacts at the instant ofseparation thereof, and a lost motion connection controlled by said means for disconnecting the fuse from said contact.

16. In an electric switch, a movable switch blade, a movable quick break blade, a movable fuse blade, and lost motion connections for operating the two last. mentioned blades from the first blade.

17. In an electric switch, three movable contacts, means effective responsive to a predetermined movement of one of said'contacts for opening the other two contacts successively at predetermined speeds regardless of the speed of opening of the first contact, said means including a lost motion connection.

18. In an electric switch, a switch blade pivoted at one end and adapted to establish a connection at the other end, a quick break blade pivoted to the main blade intermediate its ends, a lost motion connection between said blades, means for locking the quick break blade in position, means for locking the first mentioned blade to the quick break blade, said first mentioned locking connection being controlled by the movement of the first mentioned blade.

19. In an electric switch, a main switch I tion with respect to said first mentioned blade.

20. In an electric switch, a main switch blade pivoted at one end, a link pivoted to said blade, an auxiliary switch blade pivoted to said link, resilient means for holding said second mentioned blade in position with respect to said first mentioned blade, and locking means for locking the two switch blades together.

21. In an electric switch, a main switch blade pivoted at one end, a link pivoted to said blade, an auxiliary switch blade pivoted to said link, resilient means for holding said second mentioned blade in position with respect to said first mentioned blade, and locking means for locking the two switch blades together, said locking means being fixed to one of said blades and constituting the means for moving said blade.

22. The combination, in a circuit interrupter having main and auxiliary stationary and movable contact members, of a separate resiliently supported contact member adapted to engage the movable auxiliary contact member before the said movable auxiliary contact member comes into engagement with the stationary auxiliary contact member.

23. The combination, ina circuit interrupter having main and auxiliary stationary and movable contact members, of a separate resiliently supported contact member adapted to engage the movable auxiliary contact member before the said movable auxiliary contact member comes into engagement with the stationary auxiliary contact member, said separate contact member becoming disengaged from the movable contact member only after its disengagement from the stationary auxiliary contact member.

24. The combination, in a circuit interrupter having main and auxiliary stationary contact members, of a separate resiliently mounted stationary contact member, a main bridging member, and an auxiliary movable contact member that successively engages the resiliently mounted contact member and the stationary auxiliary contact member.

In witness whereof, I hereunto subscribe my name this 26th day of April, 1927.

NICHOLAS J. CONRAD. 

